Indicator for spark-plugs.



A. R. LAMBERSON. INDICATOR FOR SPARK PLUGS. APPLICATION FILED DEO.1,1910.

Patented June 20, 1911. 5

WITNESSES IIVVE/VTOI? lyw m AddisonRLamberson p 7 f Br I ATTORNEYS err ADDISON R. LAMBERSON,

or ALBANY, NEW YORK.

INDICATOR non srAnK-rrmes.

Specification of Letters latent. Patented June 2Q, .1911. Y Application filed December 1, 1910. Serial No. 595,023. I I

To all whom it may concern:

Be it known that I, ADDISON R. LAMBER- SON, a citizen of the United States, and a resident of Albany, in the county of Albany and State of New 'York,'have invented a in the vacuum bulb, the latter becomingluminous and thereby visible through the peep-hole to theoperator. In thisconnection- I call attention to a few facts well known in relation to the operating and testing 0f spark plugs nsed in connection with internal combustion engines, The spark plug is ordinarily constructed, but provided with a spark gap'which is normally open-that is to say, comprises two terminals whichare ordinarily separated by an air gap. If, now, it happens that for any reason'a quantity of material of practic'ally any kind gets into the spark gap, a short connection is almost invariably made.

This is true even if'the gap b'e bridged by a volume oflubricating oil, as this oil is apt to contain either particles of carbon small particles of metal, or impurities of other kinds in-the form of dust. Where a spark' plug is in perfect condition there is no short connection across the gap, and consequently the potential of the portion of the plug in connection with the source ofelectric supply is raised considerably each time current is supplied to the plug. If, on the other hand, owing to the fouling of the plug-that is, owing to the formation of a short connection in the spark gap as above described-it happens that there is a short connection established across the gap and.

current is supplied to the plug as usual, the

potential of the plug or of any-portion thereof is not raised to a very great extent. When high tension currents are employed, as is generally the case, the potential is, of course,

very high when the plug is in perfect condition, and is comparatively low when the plug is operating badly, or, at least, when the plug is fouled as above described.

What I seekto do is to provide an indicator having generally the form of a tube which may be carried in the pocket or disposed upon any convenient part of a vehicle and used from time to time by applying a portion of it directly to the binding postof a spark plug, the operator looking into the end of the tube and ascertaining whether or indication being made by the glow of a vacuum lamp contained within the tube.

Reference is to be had to the accompanying drawing-forming a part of this"'specification through my indicator as momentarily applied to a spark plug.

A piece of steel tubing 1 is threaded internally at 2 and fitted into this end of the tube is a ring 3 of wood. This ring is provided with an opening '4: which, because of its nature, I designate as a peep-hole. Mounted within the tube 1 is a contact washer 5 provided with an inwardly projecting annular .fiange 6. This contact washer, including its portion 6, is madeof metal. At 7 is a conical head made of insulating material and provided with a threaded portion which mates a threaded portion 9 of the tube 1, so that the conical head 7 may be detachably connected with a cylindrical passage 10 and fitted into the latter is a head 11. A pin 12 is connected with this head and is provided with a point which serves practically as the point of the conical head 7. A spiral spring 13 is disposed within the passage 10 and engages the ead 11. h v

At 14 is a vacuum bulb, or, popularly speaking, a small incandescent lamp, having ing threaded as usual. The filament of the lamp is shown'at 16*and is in metallic communication with both terminals. The s ring 13 engages the terminal 15, although if desired the diameter of the spring 13 may be reduced and the spring may make engagement with the inside terminal only.

At 17 is a spark plug whiclris provided with a spark ga' 18 and with a threaded portion 19 where y it is detachably mounted tion, in which the figure shows a cross secnot the spark plug is in good condition, the

the tube. The conical head is provided with the usual inside and outside terminals, the outside terminal being shown at 15 and being post 22 and portions of the plug immediately adjacent to the same is raised considerably every time a high tension current is supplied through the Wire 21. When, however, the spark gap 18 is fouled sothat the high tension current escapes easily across it, the potential of the binding post 22 is raised but little if any.

The operator, in order to test the condition of the spark plug, and particularly of the spark gap 18, takes the tube in his hand and applies the point of the pin 12 to the binding post 22. The body of the operator handling the device above described serves in a measure as a conductor, and in the drawing this conductor is represented diagrammatically at 23.

The operation of my device is as follows: Assume that the operator wishes to ascertain the condition of the spark gap 18 and has applied'the tube as above described, so that the point ofthe pin 12 engages the binding post 22. If, now, it happens that the spark gap 18 isfouled so that the high tension currents pass readily across this-gap, and consequently thepotential of the bmding 0st 22 is not raised to any great extent, llttle or no current can flow through the pin 12 and parts connected electrically therewith. The operator now looks through the peephole 4, and seeing no illumination within v the tube, knows that the spark gap 18' is fouled, or at least that there is something wrong with the spark plug. Suppose, however, that the sparkgap 18 is in ood condition. The potential of the binding post 22 rises very high whenever asupply of high tension current is sent through the wire 21 to the binding post 22. The operator holding the tube 1 in his hand and standing upon the ground or upon a floor affording an easy path for a discharge of high tension current, causes the current to flow. The passage of the current is as follows: Wire 21, binding post 22, ,pin 12,

head 11, spring 13, terminal 15, to filament 16, thence through the rarefied air or other gas Within the vacuumbulb 14 and through the glass bulb to the portion 6 of the contact washer 5, thence through the substance of the tube 1. to the operators body (represented diagrammatically by the conductor 23), to floor or ground, thence to source of supply, and finally back to the wire 21. The

passage of the current from the filament 16 through the vacuum to the metallic flange 6 causes the lamp to become illuminated, the nature of the discharge through it being a so-called brush discharge, the illuminating of which is greatly improved by the fact that the lamp contains a so-called vacuum. The effect is somewhat upon the order of that produced in a Geissler tube.

The operator now lookingthrough the peep-' hole 4, observes within the tube the glow made by the lamp 14, and noting the perfection of the glow is able thereby to ascertain that the plug is in good condition. If

the spark gap 18 be only partially fouled, 30

a partial glowof the lamp gives a quantitative indication, thereby enabling the operator to ascertain, roughly at least, thedegreeof disability under which the spark gap is acting. The operator in practice merely 35 picks up a tube and touching its point successively to the different binding posts repre senting the several spark plugs, glances through the peep-hole 4 in each instance as he applies the tube, and in this manner detects, practically in an instant, anyone or more of thespark plugs in which the spark gap is fouled. i

I do not limit myself to any particular materials to be employed in the construction of this device. Neither am I limited to any special shape for the vacuum lamp, nor to any particular kind of rarefied gas or vapor which it may contain. Neither do 1 limit myself to the particular arrangement of the several parts herein shown, the scope of my invention beingcommensurate with my claims; While inthis instance I have shown the pin 12 as engaging the binding post of a spark plug, it should be understood that any other suitable contact member of terminal can be employed instead of the pin 12, and that for purposes of testing the pin, it can be brought into contact with any sort of conductor, the current of which 1L6 is to be tested.

Having thus described myinvention, I claim as new and desire to secure by Letters Patent:

1. The combination of a metallic tubular 11 member, a head closing one end of said tubular member and made of insulating material, a metallic member mounted within said head and provided with a portion to be applied to a conductor, a spring mounted with- 12 in said head and in electrical communication with said metallic tubular member, a lamp disposed within said tubular [member and engaging said spring, and a contact washer connected with said tubular member and engaging a part of said lamp.

2. The combination ofa tubular metallic member, a contact washer mounted therein, a lamp-bulb disposed within said tubular member and providedwith a vacuum globe 995,878 i am engaging said contact washer, said lamp bel to said contact washer, electrical connections,

ing further provided with a conducting one of said electrical connections beingpromember from which a discharge may take place to said contact washer, and electrical connections, one of said electrical connections being provided with a portion extending from said tubular member and adapted to be applied to a conductor.

3. The combination of a tubular metallic member, a contact washer mounted therein, a lamp bulb disposed within said tubular member and rovided with a vacuum globe engaging sai contact washer, said lam being further be! from w rovided with a conducting memich a discharge may take place vided with a portion extending from said tubular member and adapted to be ap lied to a conductor, and an annular member f itted into one end of said tubular member and provided with a peep-hole for enabling the operator to observe said lamp.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ADDISON It. LAMBERSON.

Witnesses:

FREDK. E. WADHAMS, A. MARY KRnTsoHMnn 

